Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ran Matsudaira is active.

Publication


Featured researches published by Ran Matsudaira.


Journal of Cardiology | 2014

Disease Duration and Severity Impacts on Long-term Cardiovascular Events in Japanese Patients with Rheumatoid Arthritis

Hiroshi Masuda; Tetsuro Miyazaki; Kazunori Shimada; Naoto Tamura; Ran Matsudaira; Takuma Yoshihara; Hiromichi Ohsaka; Eiryu Sai; Rie Matsumori; Kosuke Fukao; Makoto Hiki; Atsumi Kume; Takashi Kiyanagi; Yoshinari Takasaki; Hiroyuki Daida

BACKGROUND Rheumatoid arthritis (RA) increases the mortality and morbidity of cardiovascular disease (CVD). However, the relationship between RA and the risk of CVD in the Japanese population remains unclear. METHODS AND RESULTS This study comprised 571 RA patients who were admitted to Juntendo University Hospital from January 1990 to December 2000. Cardiovascular events (CVEs) were defined as cardiac death, acute coronary syndrome (ACS), symptomatic stroke, and congestive heart failure. During follow-up (mean 11.7 ± 5.8 years), 7.5% of the patients died from all causes and 11.0% experienced CVEs. The morbidity of stroke and ACS was 3.6 and 2.5 per 1000 person-years, respectively. The mean RA disease duration at enrolment was significantly longer in patients who experienced CVEs than in those who did not experience CVEs (15.0 ± 12.7 years vs. 10. 8 ± 9.7 years; p = 0.01). Physical disabilities due to RA were more severe in patients who experienced CVEs than in those who did not experience CVEs. Patients with a long RA disease duration showed significantly higher event rates (p = 0.033). Cox proportional hazards analysis identified a longer RA duration as an independent risk factor for CVD (hazard ratio 1.57, 95% CI 1.09-2.30, p = 0.02). CONCLUSION Japanese RA patients showed a relatively high incidence of CVD, despite the fact that they had few coronary risk factors. The RA disease duration was an independent risk factor for CVEs.


The Journal of Rheumatology | 2011

Anti-Ro/SSA Antibodies Are an Independent Factor Associated with an Insufficient Response to Tumor Necrosis Factor Inhibitors in Patients with Rheumatoid Arthritis

Ran Matsudaira; Naoto Tamura; Fumio Sekiya; Michihiro Ogasawara; Kenjiro Yamanaka; Yoshinari Takasaki

Objective. To study the significance of anti-Ro/SSA antibodies (anti-Ro) in the clinical response to tumor necrosis factor (TNF) inhibitors in patients with rheumatoid arthritis (RA). Methods. The clinical responses of a cohort of 190 patients with RA who were treated with infliximab, etanercept, or adalimumab (n = 112, 64, and 14, respectively) as the first biologics were examined using the Disease Activity Score in 28 joints (DAS28) at 24 weeks and the discontinuation rate at 56 weeks. The baseline characteristics of responders and the nonresponders were compared. The clinical response was compared between anti-Ro-negative and -positive patients. The factors associated with the inefficiency of TNF inhibitors were estimated with a multivariable logistic regression analysis. Results. The positive rate of anti-Ro was significantly higher in patients with no European League Against Rheumatism (EULAR) response at 24 weeks (OR 3.64, 95% CI 1.45–9.01, p = 0.003). In anti-Ro-positive patients, a moderate or good EULAR response rate was significantly lower with a sustaining higher median DAS28 (p = 0.006), and this difference was greater among infliximab-treated patients. The discontinuation rate for TNF inhibitors due to inefficacy at 56 weeks was also higher in anti-Ro-positive patients (OR 4.68, 95% CI 1.82–11.99, p = 0.0005), and 75% of these patients received infliximab. The presence of anti-Ro was strongly associated with no EULAR response at 24 weeks and a higher discontinuation rate of TNF inhibitors by 56 weeks (OR 5.22, 95% CI 1.75–15.57, p = 0.003 and OR 10.18, 95% CI 2.18–49.56, p = 0.003). Conclusion. The presence of anti-Ro might be related to the lesser clinical response to infliximab compared to other TNF inhibitors, suggesting that the presence of anti-Ro should be considered when choosing the appropriate biologics for patients with RA.


The Journal of Rheumatology | 2012

Autofeedback from ultrasound images provides rapid improvement in palpation skills for identifying joint swelling in rheumatoid arthritis.

Michihiro Ogasawara; Go Murayama; Yusuke Yamada; Takuya Nemoto; Michiaki Kageyama; Shoko Toyama; Makio Kusaoi; Shin Onuma; Takayuki Kon; Fumio Sekiya; Kaoru Sugimoto; Ran Matsudaira; Masakazu Matsushita; Kurisu Tada; Kazuo Kempe; Ken Yamaji; Naoto Tamura; Yoshinari Takasaki

Objective. Joint swelling, an important factor in the classification criteria and disease activity assessment in rheumatoid arthritis (RA), renders joint palpation a necessary skill for physicians. Ultrasound (US) examination that visualizes soft tissue abnormalities is now used to assess musculoskeletal disease. We assessed the usefulness of US assessments in enhancing physical joint examination skills. Methods. We examined 1944 joints (bilateral shoulder, elbow, wrist, metacarpophalangeal joints 1–5, and knee joints) in 108 patients with RA during April–July 2011. We first physically examined and confirmed joint swelling; subsequently, the same rheumatologist conducted US examinations and multiple assessors graded the joint swelling. When the 2 results differed, we received autofeedback from the US results to improve the physical examination skills. Results. The sensitivities and specificities of physical examination for US-detected swollen joint, the correlation coefficient (CC) of the swollen joint counts, and the concordance rate in each patient for joint swelling sites and power Doppler (PD)-positive sites with the κ coefficients between the physical and US examinations were compared over time. We found that the sensitivity of physical examination increased by 42 percentage points (pp), while the specificity decreased by 18 pp. The average CC in June–July was greater than that in April–May. The percentage of κ coefficients > 0.8 increased from 8.8% to 17% for joint swelling and from 8.3% to 14% for PD-positive sites. Conclusion. Our results suggest that autofeedback from US assessment provides quick improvement in palpation skills for identifying joint swelling in patients with RA.


Jcr-journal of Clinical Rheumatology | 2010

Observational cross-sectional study revealing less aggressive treatment in Japanese elderly than nonelderly patients with rheumatoid arthritis.

Michihiro Ogasawara; Naoto Tamura; Shin Onuma; Makio Kusaoi; Fumio Sekiya; Ran Matsudaira; Kazuo Kempe; Ken Yamaji; Yoshinari Takasaki

Background:Elderly patients with rheumatoid arthritis (RA) have more aging-related complications than nonelderly patients with RA. Objectives:The objective of the study was to investigate the treatment status of elderly patients with RA. Methods:Between January and March 2008, 969 patients with RA were enrolled in this observational cross-sectional study. Prescription of disease-modifying antirheumatic drugs (DMARDs) and corticosteroids and laboratory data related to RA, including matrix metalloproteinase 3, rheumatoid factor, and anti-cyclic citrullinated peptide antibody levels, were compared between the elderly and the nonelderly patients. Results:Fewer DMARDs were prescribed to the elderly patients (1.40 [SD, 0.57] vs. 1.51 [SD, 0.61]; P = 0.029). Furthermore, a lower percentage of patients received methotrexate (MTX) (47.2% vs. 56.9%; P = 0.0001), a lower average dosage of MTX was administered (5.46 [SD, 1.66] mg/wk vs. 5.96 [SD, 1.77] mg/wk; P = 0.0001), and fewer biologic DMARDs were used (1.46% vs. 5.59% for infliximab, P = 0.0008; 0.58% vs. 3.19% for etanercept, P = 0.0038) in the elderly group. The laboratory data suggested that the disease status was uncontrolled to a greater extent, and complications were more common in the elderly group. Conclusion:Elderly patients with RA receive less aggressive treatment than nonelderly patients with RA, despite laboratory evidence for poorly controlled disease status among the elderly. The use of a less aggressive regimen could be attributed to the higher prevalence of complications and problems. Therefore, the elderly with RA should be considered a different patient population from the viewpoint of treatment and be administered specialized medical care.


Modern Rheumatology | 2009

Anti-proteasome activator 28α is a novel anti-cytoplasmic antibody in patients with systemic lupus erythematosus and Sjögren’s syndrome

Masakazu Matsushita; Ran Matsudaira; Keigo Ikeda; Masuyuki Nawata; Naoto Tamura; Yoshinari Takasaki

We evaluated the extent to which anti-proteasome activator (PA) 28α antibodies act as anti-cytoplasmic antibodies in systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS). Sera from 46 SLE patients without SS, 11 SLE patients with SS, and 45 primary SS patients were tested. Using anti-PA28α and anti-PA28γ (Ki) antibodies purified from nitrocellulose membranes onto which recombinant PA28α and Ki had been transferred, the cellular distributions of the targeted antigens were analyzed immunohistochemically. In addition, the incidence of anti-PA28α antibodies was compared with those of other anti-cytoplasmic antibodies. Immunofluorescent staining showed that purified anti-PA28α antibodies reacted with the cytoplasm of HEp-2 cells, whereas purified anti-Ki antibodies reacted with nucleoplasm. Among the 15 SLE patients without SS, the six SLE patients with SS, and the 30 primary SS patients who were anti-cytoplasmic-antibody positive, anti-SS-A/Ro antibodies were the most frequently detected (53, 67, and 70%, respectively); anti-PA28α antibodies were, respectively, detected in 33, 50, and 40% of those patient groups, incidences that were higher than those of anti-ribosomal P, anti-smooth muscle and anti-mitochondrial M2 antibodies. These results show that anti-PA28α antibodies are major anti-cytoplasmic antibodies in patients with SLE and SS, and the distinct cellular distributions of PA28α and Ki suggest these proteins are associated with different cellular functions.


Annals of the New York Academy of Sciences | 2003

Analysis of the Structure of Proteasome‐Proliferating Cell Nuclear Antigen (PCNA) Multiprotein Complex and Its Autoimmune Response in Lupus Patients

Yoshinari Takasaki; Kazuhiko Kaneda; Ken Takeuchi; Ran Matsudaira; Masakazu Matsushita; Hirofumi Yamada; Masuyuki Nawata; Keigo Ikeda; Hiroshi Hashimoto

We have recently found that the PCNA multiprotein complexes (PCNA complexes) associated with cell proliferation can be purified using monoclonal antibodies (mAbs) to PCNA.1 We attempted to analyze the structure of the complexes and found that proteasome, which had been known as an ATP-dependent proteolytic enzyme involved in antigen presentation on class I major histocompatibility molecules, was one of the elements of the PCNA complex. We also found that there was an autoimmune-response linkage between PCNA and proteasome.


Revista Brasileira De Reumatologia | 2017

A hepcidina‐25 dá uma indicação da eficácia terapêutica do tocilizumab na artrite reumatoide – Relação entre a atividade da doença na artrite reumatoide e a anemia

Satoshi Suzuki; Souichiro Nakano; Seiichiro Ando; Ran Matsudaira; Yoshinori Kanai; Kenjiro Yamanaka; Yoshinari Takasaki

herapy for RA has improved rapidly since the advent f biologics. However, although biologics have a greater ffect compared to that with conventional disease modifying ntirheumatic drugs (DMARDs), the cost of these newer therpies remains extremely high.1 Patients in whom biologics re effective have increased employment opportunities due to educed disease activity, meaning that the cost-effectiveness f the treatment is valid. However, in cases where the adminstration of biologics is not associated with a response, disease ctivity during the period of treatment and the progresion of joint damage place an incalculable burden on both


Modern Rheumatology | 2002

Activated peripheral blood mononuclear cells detected in lupus patients using cDNA coding for proliferating cell nuclear antigen

Yoshinari Takasaki; Soichiro Ando; Keiji Matsumoto; Hirofumi Yamada; Keigo Ikeda; Masuyuki Nawata; Masakazu Matsushita; Ran Matsudaira; Kazuhiko Kaneda; Ken Takeuchi; Yoshiaki Tokano; Hiroshi Hashimoto

Abstract The expression of proliferating cell nuclear antigen (PCNA) mRNA in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) was measured by dot blot hybridization using a PCNA cDNA, and correlated with the percentage of PCNA-positive cells detected immunohistochemically using a monoclonal anti-PCNA antibody. PCNA-positive PBMCs were detected in 72.2% of SLE patients (n = 36), which is significantly more than among healthy controls. In addition, among those in whom PCNA expression was detected, the percentage of PBMCs expressing PCNA was significantly higher in SLE patients (mean 2.5% vs. 0.15%). The level of PCNA mRNA was increased in PBMCs from 83.3% of SLE patients, and was significantly correlated with the percentage of PCNA-positive cells (r = 0.54, P < 0.01) and with the disease activity score (r = 0.56, P < 0.01). A longitudinal study of two SLE patients confirmed that PCNA mRNA expression and the percentages of PCNA-positive cells varied in parallel with disease activity. Thus, an analysis of activated PBMCs from SLE patients using PCNA cDNA may be a useful method by which to estimate SLE disease activity.


Internal Medicine | 2007

Two Cases of Refractory Wegeners Granulomatosis Successfully Treated with Rituximab

Naoto Tamura; Ran Matsudaira; Mika Hirashima; Makoto Ikeda; Michiko Tajima; Masuyuki Nawata; Shinji Morimoto; Kazuhiko Kaneda; Shigeto Kobayashi; Hiroshi Hashimoto; Yoshinari Takasaki


Modern Rheumatology | 2004

Anticyclic citrullinated peptide antibodies in patients with mixed connective tissue disease

Yoshinari Takasaki; Kenjiro Yamanaka; Chiho Takasaki; Masakazu Matsushita; Hirofumi Yamada; Masuyuki Nawata; Ran Matsudaira; Keigo Ikeda; Kazuhiko Kaneda; Hiroshi Hashimoto

Collaboration


Dive into the Ran Matsudaira's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge